1. Field of the Invention
This invention relates to an intermediate epitaxial structure and a method for fabricating an epitaxial structure.
2. Description of the Related Art
A substrate, which is suitable for epitaxial growth of an epitaxial layer in an optoelectronic device, often has poor thermal or electrical conductivity. Therefore, in consideration of the above problems and the epitaxial quality, the fabrication of the optoelectronic device usually includes a step of removing the epitaxial layer from a temporary substrate used for epitaxial growth of the epitaxial layer.
Usually, a sacrificial layer is formed between the epitaxial layer and the temporary substrate, and thus, the epitaxial layer can be removed from the temporary substrate by etching the sacrificial layer using a fluorine-containing etchant, such as hydrofluoric acid (HF).
However, although the fluorine-containing etchant can rapidly etch the sacrificial layer, the etchant is likely to result in corrosion of etching equipments and would be harmful to the environment.